How to replace the SD card in it

It could be the replacement SD card either needs to be formatted or is too large capacity for that camera. Some cameras have a maximum GB and will display "error" when the SD card capacity exceeds that. Try an SD card with less GB storage.

It could be that you are using a corrupted card, in which case you can correct this by just buying a new SD card.

if this is not the case, find solutions to other error problems with SD cards here:
SD SDHC Card Problems and Fixes Card Locked Card Error No Memory Card...

plug it into your pc/laptop via sd card slot (adapter needed if its a micro sd) or through a usb memory card reader. open folder to view files, then copy and paste/drag and drop the files you want into a folder on your desktop.

Click here to download recovery utility. Or using any other file recovery program you can recover the files/ photos even after formatting it.
Secondly, you can format the card through windows, using memory card reader.
and if you want to completely erase the data so that it is not recoverable is to overwirte all data with some other files that are not sensitive and filling the disk completely.

Also, click here to get more information on the issue


Hope this helps!
CreativeTECH

SD cards allow you to store digital information; you can use SD cards with most electronic devices like digital cameras and computers.
An SD card will become write protected if the switch on the card is placed on the "Lock" position. This prevents any information on the card from being altered or deleted.
If you wish to add, delete or change any of the information, you must remove the write protection.
Remove the SD card from the computer or digital device.
Locate a switch on the bottom or side of the SD card.
Move the switch to the "Unlocked" position to remove the write protection.
If you do not have a switch, you will need to remove the write protection with your computer.
Insert the SD card into your computer's card reader or back into the digital device.
You can now save and change information on the card.

once you format the sd card, the computer changes the management and sytem files and makes the sd card ready for use with the computer. so you should be getting an format error.it's recommended that you format the recording media using the device you intend to use it with.i this case, since your using a camera, format the sd card using the camera.check camera instruction manual for additional info where to pull up format option in the menu settings.hope this info helps.tnx:)

Replace the card reader, it has died - it happens. Luckily this is a cheap fix.

many of these cards from ebay are seconds and rejects there is no guarantee they will work I have had 4 personally that would not work. It costs more to send them back in some cases than to just buy one locally that you can return if it fails

Check if the SD card is iserted properly into the camera, eventually pull it out and push it back inside the camera. Also remove camera batteries , repeat the operation, and put back batteries.
If the card still does not work test the card into a different device, it is not unfrequent that an SD card comes defective from factory. In this case take the card back to the retailer and a have it changed.
If the card works on a different device, then it may be that the NV3 does not support 4 GB , there is no mention about max SD format supported in camera specs, or in the manual. In this case I suggest testing a 1 or 2 Gb card at the shop, and then buying right one.

Regards

Does SD card work in PC? HP R707 will not work with SD card larger than 2GB.